What does passion sound like? How five audiobook actors talk sexy.

This Valentine’s Day, you might whisper into your lover’s ear for a few minutes.

Pity the poor audiobook narrator who has to keep that up for hours.

It’s a challenge, particularly for the voice actors who record romance novels. Perhaps no group of people has thought more deeply about the complicated sound of passion than these narrators who speak the words that romance authors set down on paper. They literally sing the body electric.

“The sure way they touched, so obviously familiar with each other’s bodies, killed me.”

— “Dirty,” by Kylie Scott

Audiobook narrators are almost all actors or former actors, working in a field that hovers somewhere between announcing the news and performing in a play. Their full-bodied voices are as honed and sculpted as the abs of any romance novel’s cover model. They court us with the witty, tragic or suspenseful stories of wicked dukes and troubled sisters, escaped slaves and young widows, advertising executives and horny shape-shifters.

Narrator Andi Arndt (Audible/Audible)

(Audible Studios)

But the conditions of the job are anything but romantic. Andi Arndt, who won the 2017 Audie Award for Romance, says, “I sit alone in a little box and read all day.”

That sounds like the plight of some Brothers Grimm heroine, but this is no fairy tale. It’s exacting work that has given rise to a cottage industry of independent contractors who are part literary critics, part actors, part sound engineers. Many work alone, sometimes in their own homes. “When I first started,” Arndt says, “I’d have this existential moment: ‘Will anybody ever hear this?’ ”

She needn’t worry about that anymore. After recording about 250 books over the past seven years, Arndt is adored by legions of listeners, and she keeps them constantly in mind when she’s recording. “I don’t want to tire them out,” she says. “It’s not about me grabbing them by the lapels. I can’t sustain that for an eight-hour book. It’s about the author’s words.”

In a sense, the audiobook narrator participates in a ménage à trois with the novelist and the listener. If that relationship works, the narrator enhances the reader’s experience — but never dominates it.

Kat Lambrix, director of Audible Studios (a subsidiary of Amazon, whose founder, Jeffrey P. Bezos, owns The Washington Post), says she wants voice actors who can understand each romance novel on an emotional level. “Are they going to be true to the ethos of the story?” she asks. “Are there double-entendres they’re going to hit just right? Are they going to be able to embody the writer and the characters?”

She acknowledges that “there are so many different ways that people’s voices can embody sexiness,” but it all comes down to one powerful but ineffable tone in the actor’s voice: “When you’re doing romance, intimate is the most important quality.” The best narrators “take you along the journey with them, and you’re in the room with them and feeling those emotions along with them.”

“From out of memory, an image came unto his mind and took his breath away. It was of a tall slender female.”

— “The Chosen,” by J.R. Ward

When the stories are very intimate, even erotic, that can get touchy.

Narrator Jim Frangione (Penguin Random House/Penguin Random House)

Jim Frangione, an actor who narrates J.R. Ward’s popular Black Dagger Brotherhood novels, says, “You really have to stay lubricated. I drink a lot of hot tea when I’m recording.” If you know Ward’s paranormal romance stories about vampire warriors, you can understand why. “You have to give it some authenticity. You have to ‘go there’ with your voice,” Frangione says. “I don’t smoke, but if I did, I’d share a cigarette with my engineer afterwards.”

“Don’t look through the glass at the engineer!” warns Amanda Ronconi, who has recorded about 70 romance novels. Once you get the giggles, you’re done, she says. You’ve got to stop, clear your mind, take a walk. When Ronconi is recording particularly erotic stories, her only goal is to stay in the character’s head. “That helps find that balance,” she says, “so that it doesn’t become pornographic.” The last thing she wants in those moments is for the engineer — invariably a young man — to stop her and ask, “Can you say that again?”

As a rule, romance listeners don’t want to hear a 1-900 voice: No moaning, no groaning. Keep it subtle. No matter how explicit the scene may be, some things need to be left to the imagination. A great voice evokes shades of grey.

Narrator Amanda Ronconi (Audible/Audible)

Narrator Karen White (Colette Blonigan/Colette Blonigan)

Karen White, who has recorded more than 350 audiobooks, says the finest compliment she ever received was from a reviewer who said that she reads “sex scenes in a way that doesn’t make a listener feel like they’re a voyeur or in that creepy way that makes you feel like you’re listening to someone’s sex act.”

Instead, White says, “I focus on the emotions that people are feeling, even if I’m reading words that are about . . . specific parts. There are no sound effects. That would be really strange. When people get too into it, and there’s a lot of panting, listeners tend not to like that. Our training is to make the voice connect with what we’re feeling. That works better than having a breathy, sexy voice. If you start listening to that, maybe the first paragraph it’s great, but then you fall asleep.”

Such emotional sensitivity is exactly what best-selling romance novelist Emma Chase is looking for. “You don’t want to be uncomfortable with those scenes,” she says. “The audiobook experience — hearing the words outside the book — heightens everything for the listener,” which makes the voice actor’s job even more crucial. “The humor is funnier. The romance is more passionate. The sexy moments make you blush a little more.” The first time she heard the recording of one of her novels, she admits, “I just kind of turned beet red. Who wrote that?”

Chase wrote her upcoming novel, “Getting Schooled” (Audible Studios), specifically for the audio format, an increasingly common approach that subtly changes the conditions of composition. “I had in mind what it would sound like to the listener,” Chase says. “And I kept in mind — particularly with love scenes — the gasping and some of the words that you use, making sure it would sound good. A talented narrator will be able to take that scene and be bold with it.”

But getting hot and bothered is hardly the most challenging aspect of recording romance novels. A year or two may pass between novels in a popular series, but a listener might binge-listen to that entire series in a week, and her favorite character has got to sound consistent from book to book. Like other narrators, White records and stores voice samples of every character she reads so that she can go back and remind herself exactly how that doctor or sister or lieutenant sounds. “There are subtle differences,” she says, “a lot of different factors you can change: pitch, tone, accent, pace and other things that affect the feel of the voice.”

Narrator Adenrele Ojo (Penguin Random House/Penguin Random House)

Adenrele Ojo, an actress who narrates and directs audiobooks, draws an analogy to film. “In a movie, we have the music and the camera shots,” Ojo says. But with an audiobook, “we’re framing all the shots for you. That comes from the voice — a little sexiness, a little raspy sometimes. The pacing is always changing depending on what’s happening in the scene. When you do get in those more romantic moments, is it clumsy, is it sexy, is it scintillating? That will tell you how to tell the story, which will help keep them enthralled.”

In some ways, the process is no different from romance itself. “Slow it down; take your time with this,” Ojo tells the narrators she’s directing. “If you find a really nice moment, you want that moment to live, to really live for the listener. Oh, oh, oh — can you just do it again?”